What is an AGM Battery?

Batteries have taken the world by storm in recent times. One of the reasons is their increased usage of vehicles. AGM batteries have also gained prominence in the world of batteries. So, you must wonder what an AGM battery is. And how it differentiates itself from other kinds of batteries. Replacing your lead-acid battery with an AGM battery is a good idea. But it costs more than twice the battery you’re using.

Let’s look at what an AGM battery is and how it is different.

Introduction to AGM Batteries

AGM is the abbreviation for “Absorbent Glass Mat”. It is the feature that differentiates this battery from other ones. You may call them the cousins of “Valve-Regulated Lead-Acid (VRLA)” batteries. However, they are quite different from conventional flooded lead-acid batteries. It is due to their design, which also makes them reliable and safe. These batteries have a high reserve capacity. It is the reason why they provide steady power for longer periods.

The main component of this battery is a glass mat separator that contains electrolytes. This mat is present between the positive and negative plates of the battery. It ensures a controlled and streamlined flow of ions. It is one of the features that sets this battery apart.

Working of AGM Batteries

AGM separator or thin glass mat is the reason behind its efficient performance. However, these batteries work the same way as conventional lead-acid batteries. But there are some differences as well. 


The thin glass mat absorbs and retains the electrolytes during the charging cycle. It also prevents spillage and saves the battery from maintenance. It also means you can install these batteries in any position. The reason is that the risk of leakage is out.


These batteries use a unique process of recombination. During charging and discharging cycles, gas is produced. It happens in all conventional and non-conventional batteries. AGM batteries do not release that gas into the atmosphere. Rather, they tend to recombine it within the battery. So you don’t need to top up the electrolyte anymore.

Low Resistance

Some flooded lead-acid batteries have high internal resistance. But, this is not the case with AGM batteries. As a result, charging and discharging happen quickly. And you can use them for high-demand applications as well.

The glass mat allows the plate material and battery acid to react faster. Since the electrolyte is a mixture of water and sulfuric acid, the reaction produces hydrogen and oxygen during charging. These batteries reabsorb these gases. All in all, the AGM separator is what makes the battery work.

Advantages of AGM Batteries

AGM batteries have several benefits compared to traditional lead-acid batteries. Here are some of them:

Quick Charging

AGM batteries can charge in no time. But they take a lot of time to discharge. They have a high charge acceptance rate, which is not the case with most other batteries. This feature becomes important when you need quick power recovery. Auto start/stop machines are an example of this.

Longer Lifespan

AGM batteries last longer than any traditional batteries. One of the reasons is their low self-discharge rate. So, when you’re not using them, the battery will not discharge.


The electrolytes do not saturate the AGM separator completely. Also, the liquid doesn’t expand as much as in other lead-acid batteries. So, fewer electrolytes indicate the lesser weight of the battery. It means the battery will bear freezing and won’t damage the plates. Therefore, these batteries are more durable.


As mentioned above, these batteries do not require any maintenance. Also, you don’t need to top up the electrolyte quite often. So it is easy to maintain these batteries.

They are spill-proof as well. So, there is a relaxation about their transportation as well. So, all you need is to follow the instructions on the datasheet.

Vibration Resistance

AGM batteries have low internal resistance. But they are also resistant to shock and vibration. It makes them ideal to use in vehicles where constant motion is there. These batteries become even more important during off-road driving. 

Deep Cycle Capabilities

You may use these batteries for deep-cycle applications as well. For example, you can power off-grid solar systems, RVs and boats with AGM batteries. It makes them a versatile option in the world of batteries.

AGM batteries have various advantages over other batteries. You can use them in modern vehicles to provide reliable power. You may use them in marines to withstand the rigors. You can also avail of their deep cycle applications. The best part is that they have a key role in solar systems. You can place these batteries to store the excess energy your solar system generates. And last but not least, you may use them as a backup power source.

You can make them your first choice if you are to avail yourself of any of the benefits mentioned above. But don’t forget to consider the factors given below. The reason is that you’ve to research according to your needs, not on the basis of the benefits.

Factors to Consider Before Buying AGM Batteries

Before you buy AGM batteries, make sure to consider the following factors:

Charging System

AGM batteries are not for all types of vehicles. So, don’t forget to verify if your charging system can accommodate AGM batteries. Or else you’ll have to replace them.


AGM batteries are costly as compared to other lead-acid batteries. So, consider the long-term benefits as well before buying these batteries.


Don’t forget to ensure that your vehicle is compatible with AGM batteries. For that, go through the manual and then decide.


Vehicles have evolved quite a bit in recent times. As a result, their power needs have also increased. To meet those needs, you need modern battery technology. An AGM battery is one of those inventions that can solve your problems. It is easy to charge, requires no maintenance and can last long enough. The only disadvantage is that they are costly. But you can pay for something long-lasting. So, leave the traditional lead-acid batteries aside and try these modern batteries.

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